Real-time Analysis of the Spinmotive Force due to Domain Wall Motion

Jun’ichi Ieda,Sadamichi Maekawa,Yuta Yamane 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.12

Using numerical simulations, we study the spinmotive force induced by domain wall motion in ahigh magnetic field region far above the Walker breakdown field. We find that the DC componentof the spinmotive force scales with the applied magnetic field even in a field range where the wallmotion is no longer associated with periodic angular rotation of the wall magnetization. As the fieldis increased, spikes in the voltage signals start to appear, which are mainly attributed to vortex corecollisions, nucleation, and annihilation, and this tendency is enhanced with further increases in thefield. At high fields, the slope of the generated DC voltage vs. applied field curve is expected todepend only on the spin polarization of conduction electrons and, thus, can be used to accuratelydetermine the degree of spin polarization in various materials.

日本 東洋史學의 韓國認識

아오야기 준이치(靑柳純一) 부산대사학회 2000 역사와 세계 Vol.- No.24

Enzyme Sensors Modified with Avidin/Biotin Systembased Protein Multilayers

Jun-ichi Anzai,Xiao-Yan Du,Tomonori Hoshi,Yasuhiro Suzuki,Hiroki Takeshita,Tetsuo Osa 한국분석과학회 1995 분석과학 Vol.8 No.4

A note on almost contact Riemannian 3-manifolds II

Jun-ichi Inoguchi 대한수학회 2017 대한수학회보 Vol.54 No.1

We classify Kenmotsu 3-manifolds and cosymplectic $3$-mani\-folds with $\eta$-parallel Ricci operator.

Thermoforming of Braided Thermoplastic Composite Tubes

Jun-ichi OZAKI,Ken-ichi MANABE 한국소성가공학회 1997 플라스틱가공 심포지엄(한일 공동 세미나) Vol.1997 No.8

Design of Flux-Axis Angular Speed Estimation using Induced Voltage in Speed Sensor-less Field Oriented Control for Induction Motor

Jun-ichi Itoh,Kazuya Kawai,Koroku Nishizawa,Hiroki Watanabe 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

This paper proposes a design method of the flux-axis angular speed estimation using induced voltage in a speed sensor-less field oriented control for induction motor (IM) drive systems. In this method, the d-axis induced voltage is regulated to zero by a feedback control to estimate the fluxaxis angular speed. A low pass filter (LPF) is necessary in this estimation to avoid the recursive calculation. In this paper, the design method of compensation gain kpem and the cut-off angular frequency of LPF ωlpf are considered. As a result, the relation between kpem, ωlpf, convergence time of the d-axis induced voltage have a match to the equation and designed model in this paper. Furthermore, the maximum error between the simulation and estimated results of the time constant of the flux-axis angular speed introduced due to LPF is 3.7% when ωlpf is 200 rad/s. As the experimental results, when a torque step of 100% is applied to the induction motor, the convergence time of the motor speed is 1.6 s as the worst case with kpem set as 2.0 p.u. and the cut-off angular frequency set as 1000 rad/s. However, if kpem is set as 2.0 p.u. and ωlpf is set as 400 rad/s, the convergence time of the motor speed is 0.43 s as the best case, which is reduced by 73.1% compared to the worst case. As the result, kpem should decide by the target steady-state error, lpf should bigger than the cut-off angular frequency of the PI controller ωASR. Where, if the ωlpf is high, the convergence time of the motor speed is high.

Voltage Unbalance Compensation Method with Zero Voltage Switching for Series Connected Switching Devices

Jun-ichi Itoh,Ryosuke Iso,Hiroki Watanabe 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

This paper proposes a voltage unbalance compensation method of series-connected switching devices for high voltage application such as DC distribution systems. In the series connection, a turn-off voltage unbalance occurs in switching devices due to a parasitic parameter mismatch and a switching timing mismatch among switching devices. In this paper, a capacitor snubber and Zero Voltage Switching (ZVS) operation are utilized to reduce voltage unbalance. In particular, the proposed method reduces the parasitic capacitor (collector-emitter capacitance) mismatch among series-connected devices by a capacitor snubber circuit, whereas the switching losses are effectively reduced by ZVS. As the simulation results, it is confirmed that the collector-emitter voltage unbalance is reduced by 88% by the proposed method in comparison with a snubber-less configuration. Finally, in order to confirm the effectiveness of the proposed method, experiments with a test circuit applied with the proposed method are conducted. According to the experimental results, the voltage unbalance is reduced by 86.0% due to the application of the proposed method.

Most Highly Cytokinergic IgEs Have Polyreactivity to Autoantigens

Jun-ichi Kashiwakura,Yoshimichi Okayama,Masutaka Furue,Kenji Kabashima,Shinji Shimada,Chisei Ra,Reuben P. Siraganian,Yuko Kawakami,Toshiaki Kawakami 대한천식알레르기학회 2012 Allergy, Asthma & Immunology Research Vol.4 No.6

Purpose Monomeric IgE molecules, when bound to the high-affinity receptor, exhibit a vast heterogeneity in their ability to induce survival promotion and cytokine production in mast cells. At one end of this spectrum, highly cytokinergic (HC) IgEs can induce potent survival promotion, degranulation, cytokine production, migration, etc., whereas at the other end, poorly cytokinergic (PC) IgEs can do so inefficiently. In this study, we investigated whether IgEs recognize autoantigens and whether IgEs' binding of autoantigens correlates with difference s in HC versus PC properties. Methods Enzyme-linked immunosorbent assays were performed to test whether IgEs bind antigens. Histamine-releasing factor in human sera was quantified by western blotting. Cultured mast cells derived from human cord blood were used to test the effects of human sera on cytokine production. Results Most (7/8) of mouse monoclonal HC IgEs exhibited polyreactivity to double-stranded DNA (dsDNA), single-stranded DNA (ssDNA), β-galactosidase, thyroglobulin and/or histamine-releasing factor. By contrast, mouse PC IgEs failed to react with these antigens. A human monoclonal HC IgE also showed polyreactivity to histamine-releasing factor, dsDNA and ssDNA. Interestingly, sera from atopic dermatitis patients showed increased reactivity to ssDNA and β-galactosidase and increased levels of histamine-releasing factor. Some atopic dermatitis patients, but not healthy individuals, had substantial serum levels of HRF-reactive IgE. Sera from atopic dermatitis patients with high titers of DNA-reactive IgE could induce several fold more IL-8 secretion in human mast cells than sera from healthy individuals. Conclusions The results show that most HC, but not PC, IgEs exhibit polyreactivity to autoantigens, supporting the autoimmune mechanism in the pathogenesis of atopic dermatitis.

A New Formalism for Lexical Transfer

Jun-ichi, Tsujii,Kimikazu, Fujita 서울대학교 어학연구소 1990 語學硏究 Vol.26 No.4

The lexical transfer has been one of major sources of difficulties in MT. Apart from difficulties of selecting appropriate target equivalent words, systematic structural correspondences between two languages are often violated by idiosyncracies of lexical correspondences. We can hardly expect to have systematic theories of lexical transfer which generalize idiosyncracies in lexical correspondences. What we can do is to prepare a framework in which we can accumulate systematically idiosyncratic knowledge concerned with lexical correspondences. In this paper, we propose a framework based on bilingual signs for lexical transfer. Through definitions of bilingual signs, not only local linguistic structures of two languages but also predicates which are used for specifying extra-linguistic knowledge are related with each other. Furthermore, by using explicit specifications of mutual relationships between bilingual signs, the system can formulate meaningful questions for disambiguating "transfer ambiguities" during lexical trnasfer. Compared with converntional bilingual dictionaries, our proposed framework has several desirable properties such as declarativeness, reversibility and flexible interface with extralinguistic processings. A rough sketch of the transfer phase which is based on constraint relaxation is also given.

Voltage Control Method in Non-linear Dead-time Effect Region for Dual Active Bridge DC-DC Converter

Jun-ichi Itoh,Kengo Kawauchi,Hayato Higa,Hiroki Watanabe,Keisuke Kusaka 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

This paper proposes a voltage control method for a Dual Active Bridge (DAB) converter with three-level operation in the dead-time effect region. The non-linear transmission power error is reduced by controlling the zero current phase to the dead-time or more because the nonlinear error of the transmission power occurs when the inductor current reaches zero during the dead-time. In addition, the voltage control is operated under the linear region which is decided from the output current and the zerovoltage period. The validation of the proposed method is confirmed by a 2.3-kW prototype. In the experiments, the non-linear error in the transmission power is reduced by 76.3%. The linearity between a control variable and an output current is confirmed. In addition, a load step between two modes of three-level operation is achieved without the dc offset in the inductor current. Moreover, the RMS value of the inductor current is reduced by 50.2% compared with the conventional triangular modulation.